Both sides claim to be in the right over the clash, where the smaller Sea Shepherd ship rammed the larger Nisshan Maru.

US Court: Sea Shepherd ‘modern-day pirates without eye patches’

Sea Shepherd’s actions have been condemned by a US federal appeals court which released its decision on the Antarctic confrontation yesterday.

In the decision, chief judge Alex Kozinski slams Sea Shepherd as “modern-day pirates” who are “disingenuous” and “destructive”.

“You don’t need a peg leg or an eye patch,” he says.

“When you ram ships; hurl glass containers of acid; drag metal-reinforced ropes in the water to damage propellers and rudders; launch smoke bombs and flares with hooks; and point high-powered lasers at other ships, you are, without a doubt, a pirate, no matter how high-minded you believe your purpose to be.”

The Japanese fleet is seeking a permanent ban on Paul Watson and the Sea Shepherd organization he founded from disrupting the annual whale hunt in the waters off Antarctica.

The Sea Shepherd's efforts are the subject of the television show Whale Wars.

In December, the same court ordered the organisation to keep its ships at least 500 yards (457 metres) from Japanese whalers. The whalers have since accused the protesters of violating that order at least twice this month.

But Watson and his lawyers contend US courts don't have jurisdiction in the Southern Ocean.